1. Technical Field
The present invention relates to a projection-type display apparatus that projects an image toward a projection surface and a method for performing projection adjustment.
2. Related Art
There has been a known technology of performing trapezoidal distortion correction, focus adjustment, and other corrections and adjustments (hereinafter referred to as projection adjustment) on an image projected (hereinafter referred to as a “projected image”) by a projection-type display apparatus represented by a projector using a liquid crystal panel or any other suitable light modulator to form an image. To perform the projection adjustment, the projection-type display apparatus projects a guide display. The guide display is a display (such as characters and icons) that prompts a user to adjust the position where the body of the projection-type display apparatus is installed (hereinafter referred to as “install position adjustment”) so that a projected image projected by the projection-type display apparatus is projected within a screen or any other suitable projection surface. The user, who visually recognizes the guide display projected on the screen, a wall outside the frame of the screen, or any other place, performs the install position adjustment. After the install position adjustment is completed, the projection adjustment is initiated (see Japanese Patent No. 3,761,563).
When the projection adjustment is performed in the order described above, however, the guide display is projected before the focus adjustment is performed on the projected image. The projected image is therefore not in focus, which makes it difficult to visually recognize the displayed contents of the guide display. As a result, the guide display cannot disadvantageously fully serve its intended purpose. Further, when the angle between the optical axis of the projection light projected by the projection-type display apparatus and the projection surface (hereinafter referred to as a “projection angle”) significantly deviates from 90 degrees, the position of the projected image within the projection surface (hereinafter referred to as a “projection position”) before the trapezoidal distortion of the projected image is corrected greatly differs from the position of the projected image after the trapezoidal distortion correction is performed. It has been therefore pointed out that only the guide display projected before the trapezoidal distortion is corrected does not allow the user to adjust the install position so that every image is projected in a user's desired projection position.